Upper Colorado Water Supply Outlook, February 1, 2014

Note: This publication is scheduled for revision. If you have feedback on content, format, or publication frequency, please contact us.
Prepared by Brenda Alcorn, Greg Smith
NOAA, National Weather Service
Colorado Basin River Forecast Center
Salt Lake City, Utah
www.cbrfc.noaa.gov

Contents

Upper Colorado Summary




*Median of forecasts within each basin.


Upper Colorado Mainstem Basin Conditions




Snow Water Equivalent in Percent of Median.
* Percent usable capacity, not percent average contents.
Click for multi-month Graph.

Gunnison Basin Conditions




Snow Water Equivalent in Percent of Median.
* Percent usable capacity, not percent average contents.
Click for multi-month Graph.

Dolores Basin Conditions




Snow Water Equivalent in Percent of Median.
* Percent usable capacity, not percent average contents.
Click for multi-month Graph.


Upper Colorado Mainstem Specific Site Forecasts (kaf)

Click site name for graph.
Forecast
Period		90%
Exceedance
Volume		50%
Exceedance
Volume		Percent
Average		10%
Exceedance
Volume
Colorado
Lake Granby, Granby, Nr April-July185 260 118 365
Willow Ck
Willow Ck Res, Granby, Nr April-July31 50 106 90
Fraser
Winter Park April-July18 25 129 31
Williams Fork
Williams Fork Res, Parshall, Nr April-July80 115 120 160
Muddy Ck
Wolford Mountain Reservoir April-July43 70 130 92
Blue
Dillon Res April-July150 210 129 275
Green Mtn Res April-July235 340 124 460
Colorado
Kremmling, Nr April-July740 1030 120 1470
Eagle
Gypsum, Blo April-July250 375 112 550
Colorado
Dotsero, Nr April-July1180 1650 118 2260
Frying Pan
Ruedi Res, Basalt, Nr April-July113 160 115 215
Roaring Fork
Glenwood Springs April-July530 735 107 1000
Colorado
Glenwood Springs, Blo April-July1750 2400 114 3300
Cameo, Nr April-July1900 2690 114 3750
Plateau Ck
Cameo, Nr April-July65 115 93 177
Colorado
Cisco, Nr April-July3450 4800 108 6950
Lake Powell, Glen Cyn Dam, At April-July4750 7250 101 10300


Gunnison Specific Site Forecasts (kaf)

Click site name for graph.
Forecast
Period		90%
Exceedance
Volume		50%
Exceedance
Volume		Percent
Average		10%
Exceedance
Volume
Taylor
Taylor Park Res April-July77 112 113 146
Almont April-July115 177 114 230
East
Almont April-July135 195 107 260
Gunnison
Gunnison, Nr April-July275 415 112 570
Tomichi Ck
Gunnison April-July46 76 103 110
Lake Fork
Gateview April-July96 136 111 185
Gunnison
Blue Mesa Res April-July500 755 112 1070
Morrow Point Res April-July570 825 111 1140
Crystal Res April-July650 925 111 1240
Muddy Ck
Paonia Res, Bardine, Nr March-June70 100 104 136
April-July70 102 105 140
Nf Gunnison
Somerset, Nr April-July210 300 102 420
Surface Ck
Cedaredge April-July10 15 89 22
Uncompahgre
Ridgway Res April-July68 97 96 138
Colona April-July89 133 97 193
Delta April-July68 110 97 169
Gunnison
Grand Junction, Nr April-July1000 1550 105 2270


Dolores Specific Site Forecasts (kaf)

Click site name for graph.
Forecast
Period		90%
Exceedance
Volume		50%
Exceedance
Volume		Percent
Average		10%
Exceedance
Volume
Dolores
Dolores April-July160 235 96 330
Mcphee Res April-July177 280 95 390
San Miguel
Placerville, Nr April-July85 130 102 177
Dolores
Cisco, Nr April-July320 540 96 740

Differences between the full period forecasts and the residual forecasts may not exactly equal the actual observed volumes due to rounding conventions (see Definitions section).

Upper Colorado End of Month Reservoir Contents (kaf)

EOM
Contents		Percent
EOM
Average		Percent
Usable
Capacity		Last Year
EOM		Last Year
%Average		EOM
Average		Usable
Capacity
untitled Colorado
Lake Granby, Granby, Nr 350.1 99 71 250.5 71 352.2 490.3
untitled Willow Ck
Willow Ck Res, Granby, Nr 8.7 110 96 8.1 101 8.0 9.1
untitled Williams Fork
Williams Fork Res, Parshall, Nr 75.9 119 78 42.5 67 63.8 96.9
untitled Muddy Ck
Wolford Mountain Reservoir 43.7 98 66 24.3 54 44.6 66.0
untitled Blue
Dillon Res 239.7 107 94 171.9 77 223.2 254.0
Green Mtn Res 82.3 102 56 61.9 76 81.1 146.9
untitled Homestake Ck
Homestake Res -9999.0 -99 -99 0.2 1 31.9 43.0
untitled Frying Pan
Ruedi Res, Basalt, Nr 79.8 110 78 62.9 87 72.4 102.0
untitled Plateau Ck
Vega Res, Collbran, Nr 15.7 125 48 8.1 64 12.6 32.9
untitled Taylor
Taylor Park Res 71.4 107 67 56.6 85 66.9 106.2
untitled Gunnison
Blue Mesa Res 388.8 76 47 328.2 64 514.6 829.5
Morrow Point Res 107.9 97 92 105.1 94 111.4 117.0
Crystal Res 15.0 98 85 15.3 99 15.3 17.5
untitled Muddy Ck
Paonia Res, Bardine, Nr 0.5 13 3 1.4 32 4.2 16.7
untitled Uncompahgre
Ridgway Res 73.8 107 89 54.8 79 69.2 83.0
untitled Dolores
Mcphee Res 184.5 68 48 190.6 70 270.9 381.1
untitled
TOTAL 1738.0 91 63 1382.3 71 1910.6 2749.1
Colorado
Lake Powell 9827.7 57 40 12176.8 70 17338.2 24322.0
untitled
TOTAL 9827.7 57 40 12176.8 70 17338.2 24322.0

Precipitation Maps




Definitions

10% exceedance forecast: Given the current hydrometeorological conditions, i.e current snowpack, soil moisture and streamflow, the volume that has a 10% chance of being exceeded. Previously referred to as "Reasonable Maximum Forecast".

50% exceedance forecast: Given the current hydrometeorological conditions, i.e current snowpack, soil moisture and streamflow, the volume that has a 50% chance of being exceeded. Previously referred to as "Most Probable Forecast".

90% exceedance forecast: Given the current hydrometeorological conditions, i.e current snowpack, soil moisture and streamflow, the volume that has a 90% chance of being exceeded. Previously referred to as "Reasonable Minimum Forecast".

Acre-Foot (af): The volume equal to one acre covered one foot deep (43,560 cubic feet). See kaf below.

Average: The arithmetic mean. The sum of the values divided by the number of values. Values from 1981-2010 are used for this publication.

Categories: Much Above Average=Greater than 130%, Above Average=111-130%, Near Average=90-110%, Below Average=70-89%, Much Below Average=Less than 70%.

CBRFC: Colorado Basin River Forecast Center.

Forecast Period: The period from April 1 through July 31, unless otherwise noted.

kaf: Thousand Acre-Feet. See Acre-Foot above.

Inflow: The volume of water that flows into a reservoir or lake.

Median: The middle value of an ordered set of values. Half of the values are higher and half of the values are lower. When the set contains an even number of values the median is the average of the two middle numbers.

NOAA: National Oceanic and Atomospheric Administration.

NWS: National Weather Service.

Rounding Conventions:
RangeRound to
0-1.990.01
2.0-19.90.1
20-1991.0
200-9995.0
1000+3 significant digits


Streamflow: The volume of water that flows past a specific stream site.

Water Year: The 12-month period, October 1 through September 30. The water year is designated by the calendar year in which it ends. Thus, the year ending September 30, 2008, is called the "2008 water year."


Additional Information

Water supply forecasts take into consideration present hydrometeorological conditions and use average basin temperatures and precipitation for the forecast period. As the forecast season progresses, a greater portion of the future hydrologic and climatic uncertainty becomes known and monthly forecasts become more accurate. For more information on the tools we use, consult Water Supply Forecasting Tools.

Volume forecasts represent adjusted flows; that is, observed flows with upstream water use taken into account. Adjusted flows will closely approximate natural or unimpaired flows. However, not all upstream diversions or impoundments are measured or quantifiable. For specific adjustments used with each forecast point, consult the Guide to Water Supply Forecasting.

The Water Supply Outlook is issued monthly January through May by the Colorado Basin River Forecast Center. It represents a coordinated effort between the National Weather Service, Natural Resources Conservation Service, Bureau of Reclamation, U.S. Geological Survey and local water district managers.

Note: Data used in this report are provisional and are subject to revision.

For more information, or to be included on the mailing list, please contact:

Colorado Basin River Forecast Center
2242 W North Temple
Salt Lake City, UT 84116
(801) 524-5130
www.cbrfc.noaa.gov


Hydrologist: Brenda Alcorn, Greg Smith